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Title: Search for Pentaquarks with CLAS

Abstract

We review the current experimental situation of pentaquark searches, and second generation experiments, with emphasis on the Jefferson Lab program.

Authors:
;  [1];  [2];  [3];  [2]
  1. Istituto Nazionale di Fisica Nucleare, Via Dodecaneso 33 16139 Genova (Italy)
  2. Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)
  3. (United States)
Publication Date:
OSTI Identifier:
20798044
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 815; Journal Issue: 1; Conference: 25. international conference on physics in collision, Prague (Czech Republic), 5-9 Jul 2005; Other Information: DOI: 10.1063/1.2173592; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CEBAF ACCELERATOR; MULTIPARTICLE SPECTROMETERS; PARTICLE IDENTIFICATION; QUARKS; REVIEWS

Citation Formats

Battaglieri, M., De Vita, R., Kubarovsky, Valery, Jefferson Laboratory, 12000 Jefferson Av., Newport News, VA 23606, and Stoler, Paul. Search for Pentaquarks with CLAS. United States: N. p., 2006. Web. doi:10.1063/1.2173592.
Battaglieri, M., De Vita, R., Kubarovsky, Valery, Jefferson Laboratory, 12000 Jefferson Av., Newport News, VA 23606, & Stoler, Paul. Search for Pentaquarks with CLAS. United States. doi:10.1063/1.2173592.
Battaglieri, M., De Vita, R., Kubarovsky, Valery, Jefferson Laboratory, 12000 Jefferson Av., Newport News, VA 23606, and Stoler, Paul. Wed . "Search for Pentaquarks with CLAS". United States. doi:10.1063/1.2173592.
@article{osti_20798044,
title = {Search for Pentaquarks with CLAS},
author = {Battaglieri, M. and De Vita, R. and Kubarovsky, Valery and Jefferson Laboratory, 12000 Jefferson Av., Newport News, VA 23606 and Stoler, Paul},
abstractNote = {We review the current experimental situation of pentaquark searches, and second generation experiments, with emphasis on the Jefferson Lab program.},
doi = {10.1063/1.2173592},
journal = {AIP Conference Proceedings},
number = 1,
volume = 815,
place = {United States},
year = {Wed Feb 08 00:00:00 EST 2006},
month = {Wed Feb 08 00:00:00 EST 2006}
}
  • We review the latest results from experiments dedicated to pentaquark searches carried out at the Jefferson Lab with the CLAS detector.
  • The reaction {gamma}p {yields} K{sup +}K{sup -}p was studied at Jefferson Lab with photon energies from 1.8 to 3.8 GeV using a tagged photon beam. The goal was to search for a {Theta}{sup ++} pentaquark, a narrow doubly charged baryon state having strangeness S = +1 and isospin I = 1, in the pK{sup +} invariant mass spectrum. No statistically significant evidence of a {Theta}{sup ++} was found. Upper limits on the total and differential production cross section for the reaction {gamma}p {yields} K{sup -}{Theta}{sup ++} were obtained in the mass range from 1.5 to 2.0 GeV/c{sup 2}, with anmore » upper limit of about 0.15 nb, 95% C.L. for a narrow resonance with a mass M{sub {Theta}{sup ++}} = 1.54 GeV/c{sup 2}. This result places a very stringent upper limit on the {Theta}{sup ++} width.« less
  • The HERA-B collaboration searched for {theta}+ and {xi}3/2 pentaquarks in the channels pK{sub S}{sup 0} and {xi}{pi} in proton-nucleus interactions at mid-rapidity and {radical}(s) = 41.6 GeV/c{sup 2}. Having found no pentaquark signals, upper limits were set on production cross sections and particle ratios.
  • A study of states and enhancements reconstructed using the invariant-mass spectra associated with strange baryons has been performed in ep collisions with the ZEUS detector at HERA using an integrated luminosity of 121 pb-1. The invariant-mass spectra were reconstructed in several kinematic regions with the main emphasis on the spectra which are sensitive to the production of pentaquarks. The candidate {theta}+ signal was found to be produced predominantly in the forward hemisphere in the laboratory frame. This is unlike the case for the {lambda}(1520) or the {lambda}c, and indicates that the {theta}+ may have an unusual production mechanism related tomore » proton-remnant fragmentation.« less
  • Using the full 1996 - 2000 ZEUS data at HERA (121 pb-1) we have searched for the {theta}{sub c}{sup 0}(3100) pentaquark in the photoproduction and DIS regime. The search has yielded negative results. The 95% C.L. upper limits on the visible rate R({theta}{sub c}{sup 0} {yields} D{sup *}p/D{sup *}) is 0.23% (0.35% for DIS)